Fiber optic bi-directional coupling lens

ABSTRACT

A component for coupling light bi-directionally between optical waveguides and optoelectronic devices is described. This component can be inexpensively manufactured and fits within the existing form-factor of fiber optic transceivers or transmitters, and has features for efficiently coupling laser light to a waveguide and light from the same waveguide to a detector. The described components can be formed as an array to operate within system that operation over parallel optical fibers. Applicability for these components is for optical time domain reflectometry, bi-directional optical communications, remote fiber sensing, and optical range finders.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of and claims the benefit of priorityunder 35 U.S.C. §120 to U.S. patent application Ser. No. 12/617,021,filed on Nov. 12, 2009, which claims the benefit of priority under 35U.S.C. §119(e) to U.S. Provisional Patent Application No. 60/113,298,filed Nov. 11, 2008, the contents of each of which are incorporated byreference in their entireties.

FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT

This disclosure was made with Government support under N00014-06-M-0208awarded by the United States Navy. The government may have certainrights.

FIELD

This disclosure relates to relates to devices that communicate overoptical waveguides. More particularly, it relates to efficientlycoupling laser light to a waveguide and light from the same waveguide toa detector.

BACKGROUND

Optical transmitters typically use a lens to couple light from a lightemitting device into an optical waveguide, such as a fiber. Inapplications such as optical time domain reflectrometry (OTDR), opticalfrequency domain reflectrometry (OFDR) and bi-directional datacommunications (BIDI), it is necessary to couple light from the lightemitter to the waveguide and couple light from this very same waveguideback to a light detecting device. These devices can be implemented in amanner to determine “breaks” in a fiber optic line.

However, such systems can be difficult to implement or require veryspecialized equipment. Therefore, there has been a long standing need inthe optical testing community for methods and systems for addressingthese and other difficulties in the electro-optical community.

SUMMARY

The foregoing needs are met, to a great extent, by the presentdisclosure, wherein in one aspect of the disclosed embodiments, a devicefor transmitting and reflecting light between a plurality of lenses isprovided, comprising: a multi-sided transparent body having an indenttherein; a light splitting surface formed integral to an interior end ofthe indent, capable of passing and reflecting split light; a first lensformed integral to a first side of the body; a second lens formedintegral to a second side of the body, wherein the first lens and secondlens are disposed in a reflected split light path of each other; a thirdlens formed integral to the first side of the body; and a reflectorsupporting angled surface formed integral to an exterior end of theindent, wherein a reflector positioned on the angled surface directslight from the third lens to the light splitting surface and directslight from the light splitting surface to the third lens.

In another aspect of the disclosed embodiments, a device fortransmitting and reflecting light between a plurality of lenses isprovided, comprising: a multi-sided transparent body, a light splittingsurface formed integral to a first side of the body, capable of passingand reflecting split light; first lens formed integral to a second sideof the body; a second lens formed integral to a third side of the body,wherein the first lens and second lens are disposed in a reflected splitlight path of each other; wherein the light splitting surface passeslight from the second lens onto a non-integral lens.

In another aspect of the disclosed embodiments, a device fortransmitting and reflecting light between a plurality of lenses isprovided, comprising: a light splitting surface capable of passing andreflecting split light based on an angle of incidence; a first lens andlight emitter combination in a first path, at an angle to the lightsplitting surface; a second lens and waveguide combination in a secondpath, substantially on an axis of the light splitting surface; and athird lens and light detector combination in a third path, at anotherangle to the light splitting surface, wherein light from the first lensand light emitter combination is bent towards the second lens andwaveguide combination, and light from the second lens and waveguidecombination is bent towards the third lens and light detectorcombination.

In yet another aspect of the disclosed embodiments, a device fortransmitting and reflecting light between a plurality of lenses isprovided, comprising: a multi-sided transparent body having a first andsecond indent therein; a light splitting surface formed integral to aninterior end of the first indent, capable of passing and reflectingsplit light; a transparent standoff that fits into the second indent; afirst lens and a third lens, each formed integral to a device side ofthe standoff; a second lens formed integral to a first side of the body,wherein the first lens and second lens are disposed in a reflected splitlight path of each other; and a reflector supporting angled surfaceformed integral to an exterior end of the first indent, wherein areflector positioned on the angled surface directs light from the thirdlens to the light splitting surface and directs light from the lightsplitting surface to the third lens.

In yet another aspect of the disclosed embodiments, a device fortransmitting and reflecting light between a plurality of lenses isprovided, comprising: a multi-sided transparent body having a first andsecond indent therein; a light splitting surface formed integral to aninterior end of the first indent, capable of passing and reflectingsplit light; a first and third lens formed integral to an interior endof the second indent; a second lens formed integral to a first side ofthe body, wherein the first lens and second lens are disposed in apassed split light path of each other; and a reflective angled surfaceformed integral to a second side of the body, wherein light from thesecond lens to the light splitting surface is reflected to thereflective angled surface and reflected to the third lens.

In yet another aspect of the disclosed embodiments, a method fortransmitting and reflecting light between a plurality of lenses isprovided, comprising: forming a multi-sided transparent body having anindent therein; forming a light splitting surface integral to aninterior end of the indent, capable of passing and reflecting splitlight; forming a first lens integral to a first side of the body;forming a second lens integral to a second side of the body, wherein thefirst lens and second lens are disposed in a reflected split light pathof each other; forming a third lens integral to the first side of thebody; forming a reflector supporting angled surface integral to anexterior end of the indent, wherein a reflector positioned on the angledsurface directs light from the third lens to the light splitting surfaceand directs light from the light splitting surface to the third lens;illuminating the first lens with a beam of light, wherein light isreflected from the light splitting surface to a waveguide disposed inline with the second lens; and receiving light from the waveguide thatis passed through the light splitting surface and reflected to the thirdlens to a light detector.

In another aspect of the disclosed embodiments, a method fortransmitting and reflecting light between a plurality of lenses isprovided, comprising: forming a multi-sided transparent body: forming alight splitting surface integral a first side of the body, capable ofpassing and reflecting split light; forming first lens integral to asecond side of the body; forming a second lens integral to a third sideof the body, wherein the first lens and second lens are disposed in areflected split light path of each other, wherein the light splittingsurface passes light from the second lens onto a non-integral lens;illuminating the first lens with a beam of light, wherein light isreflected from the light splitting surface to a waveguide disposed inline with the second lens; and receiving light from the waveguide thatis passed through the light splitting surface and reflected to thenon-integral lens to a light detector.

In yet another aspect of the disclosed embodiments, a method fortransmitting and reflecting light between a plurality of lenses isprovided, comprising: forming a light splitting surface capable ofpassing and reflecting split light based on an angle of incidence;aligning a first lens and light emitter combination in a first path, atan angle to the light splitting surface; aligning a second lens andwaveguide combination in a second path, substantially on an axis of thelight splitting surface; and aligning a third lens and light detectorcombination in a third path, at another angle to the light splittingsurface, wherein light from the first lens and light emitter combinationis bent towards the second lens and waveguide combination, and lightfrom the second lens and waveguide combination is bent towards the thirdlens and light detector combination; illuminating the first lens with abeam of light, wherein light is reflected from the light splittingsurface to a waveguide disposed in line with the second lens; andreceiving light from the waveguide that is passed through the lightsplitting surface and reflected to the non-integral lens to a lightdetector.

In yet another aspect of the disclosed embodiments, a method fortransmitting and reflecting light between a plurality of lenses isprovided, comprising: forming a multi-sided transparent body having afirst and second indent therein; forming a light splitting surfaceintegral to an interior end of the first indent, capable of passing andreflecting split light; forming a transparent standoff that fits intothe second indent; forming a first and third lens formed to a deviceside of the standoff; forming a second lens integral to a first side ofthe body, wherein the first lens and second lens are disposed in areflected split light path of each other; forming a reflector supportingangled surface integral to an exterior end of the first indent, whereina reflector positioned on the angled surface directs light from thethird lens to the light splitting surface and directs light from thelight splitting surface to the third lens; illuminating the first lenswith a beam of light, wherein light is reflected from the lightsplitting surface to a waveguide disposed in line with the second lens;and receiving light from the waveguide that is passed through the lightsplitting surface and reflected to the non-integral lens to a lightdetector.

In yet another aspect of the disclosed embodiments, a method fortransmitting and reflecting light between a plurality of lensesprovided, comprising: forming a multi-sided transparent body having afirst and second indent therein; forming a light splitting surfaceintegral to an interior end of the first indent, capable of passing andreflecting split light; forming a first and third lens integral to aninterior end of the second indent; forming a second lens integral to afirst side of the body, wherein the first lens and second lens aredisposed in a passed split light path of each other; forming areflective angled surface integral to a second side of the body, whereinlight from the second lens to the light splitting surface is reflectedto the reflective angled surface and reflected to the third lens;illuminating the first lens with a beam of light, wherein light isreflected from the light splitting surface to a waveguide disposed inline with the second lens; and receiving light from the waveguide thatis passed through the light splitting surface and reflected to thenon-integral lens to a light detector.

In another aspect of the disclosed embodiments, a device fortransmitting and reflecting light between a plurality of lenses isprovided, comprising: means for light path manipulation having an indenttherein; means for splitting light integral to an interior end of theindent, capable of passing and reflecting split light; first means forfocusing light formed integral to a first side of the means for lightpath manipulation; first means for focusing light formed integral to asecond side of the means for light path manipulation, wherein the firstand second means for focusing light are disposed in a reflected splitlight path of each other; third means for focusing light formed integralto the first side of the means for light path manipulation; and meansfor supporting a reflector integral to an exterior end of the indent,wherein a reflector positioned on the means for supporting directs lightfrom the third means for focusing light to the means for splitting lightand directs light from the means for splitting light to the third meansfor focusing light.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an embodiment showing coupling light between alight emitter and waveguide using a first surface turn light toward thewaveguide, and using this first surface to pass light from the waveguideto a second surface reflector. The second surface reflector turns thelight toward a detector.

FIG. 2 is a diagram of an embodiment showing coupling light between alight detector and waveguide using a first surface turn light toward adetector, and using this first surface to pass light from the lightemitter to the waveguide. The second surface reflector turns the lighttoward the waveguide.

FIG. 3 is a diagram of an embodiment showing coupling light between alight emitter and waveguide using a first surface turn light toward thewaveguide, and using this first surface to pass light from the waveguideto a light detector.

FIG. 4 is a diagram of an embodiment showing a transmissive system forbi-directionally coupling light between a light emitter and detector anda waveguide.

FIG. 5 is a diagram of an embodiment showing a reflective system forbi-directionally coupling light between a light emitter and detector anda waveguide.

FIGS. 6A-I are diagrams of showing exemplary methods of forming a lightsplitting surface.

FIG. 7 is a diagram of an embodiment showing a bi-directional couplingsystem constructed with individual lens components aligned to lightemitter, light detector and waveguide.

FIG. 8 is a diagram of an embodiment showing a bi-directional couplingsystem constructed as two sub-assemblies containing lens elements.

FIGS. 9A-B are diagrams of embodiments showing a bi-directional couplingsystem operating on multiple, independent light channels in an array.

FIG. 10 is a diagram of an embodiment showing a bi-directional couplingsystem combined with an optically transparent carrier that provideselectrical connectivity between circuitry and light emitter and lightdetector.

FIG. 11 is a diagram of an embodiment showing a bi-directional couplingsystem combined with electronic circuitry in communication with lightemitter and light detector.

FIG. 12 is a diagram of an embodiment showing a bi-directional couplingsystem containing features that aid in aligning light emitters and lightdetectors to a transparent carrier and features that aid in aligning abi-directional coupling element to a transparent carrier.

FIG. 13 is a diagram of an embodiment showing a bi-directional couplingsystem for applications that do not use an optical waveguide.

FIGS. 14A-D are diagrams of embodiments showing a bi-directionalcoupling system.

FIG. 15 is a diagram showing an embodiment 780 with an integratedreflector and collinear waveguide-to-light emitter configuration.

DETAILED DESCRIPTION

Introduction

OTDR is a well known method of finding the location of discontinuitieswithin the length of an optical waveguide. If a portion of a waveguideis damaged or broken, this section will reflect a portion of the lightback to the light source. An OTDR system typically operates bytransmitting a short pulse of light down the waveguide and measuring thetime delay of the light pulse reflected from the discontinuity. The timedelay is proportional to the distance traveled within the waveguide andthereby the location of the discontinuity is determined

OTDR is performed today with a specialized piece of test equipment. Toperform OTDR, the user disconnects one end of the optical link (eitheron the transmitter or receiver end) and inserts the test equipment. TheOTDR test equipment then indicates the locations of discontinuities inthe fiber path. Since fiber optical connections have traditionally beenimplemented for long distance communications, OTDR equipment is designedto measure lengths of fiber of 1000 meters or more. These applicationsare sometimes called fiber to the home, wide area networks or local areanetworks. Over these long spans, the acceptable accuracy of OTDRequipment, in terms of resolving the location of a fiber discontinuity,is not less than 1 meter.

Rather than use a specialized piece of test equipment, another method ofperforming OTDR is to implement the function within the opticaltransmitter. This would allow automated testing of the fiber link fordiscontinuities without disconnecting the link. This is highly desirablefor fiber optic networks that have the transmitters and receivers inlocations that are not easily accessible by a technician with OTDR testequipment. For example, military aircraft can have tens to hundreds offiber links that move data among sensors, displays and data processingunits. The optical transmitters and receivers are located within boxesthat are distributed across the airframe. Due to tight physical spacerequirements, the boxes are packaged in remote, hard to reach locations.Therefore, an optical transmitter with the capability to autonomouslyperform OTDR would be a great benefit to maintainers of the aircraft.

The above presented problem(s) is also found in parallel fiber opticcomponents. Parallel fiber optic components operate on multipleindividual fibers in parallel. Each individual fiber is susceptible to adiscontinuity. Parallel optic transmitters and transceivers transmitdata over these multiple fibers connected into a single package. Atransmitter or transceiver with an OTDR function embedded on each fiberchannel would allow measurement of each of the individual fibers in thelink.

Multiple modes of communication are achievable with fiber optic lines.For example, bi-directional data communications allow communicationbetween two devices over a single fiber, thus reducing the need for adedicated fiber communicating in each direction. Remote fiber sensingutilizes a laser to transmit light down an optical waveguide that isplaced in a remote environment and measure properties back-reflectedlight. The remote environments can change the reflective properties ofthe fiber by various means, including: temperature, pressure, motion,humidity, and/or chemicals. Optical range finders utilize a laser totransmit a pulse into free space and measure the time-of-flight of theback-reflected light from an object.

As further described below, various exemplary embodiments address themeans of providing bi-directional optical coupling between a singlewaveguide and a light emitter and detector devices. Such means can beapplied to single-mode and multi-mode fiber waveguides. The means can beformed as a single component in a low-cost molding process, enabling: 1)a cost efficient method of implementing bi-directional coupling withinthe existing physical envelope of a transmitter component, and 2) amechanically robust device capable of operating in harsh environmentalconditions, such as shock and vibration.

Various exemplary embodiments can provide bi-directional coupling oflight between an optical waveguide, an optical emitter and an opticaldetector. These embodiment(s) incorporate a patterned or coated surfacethat directs light from a light emitter into an optical waveguide andsimultaneously directs light from the optical waveguide into an opticaldetector. The component can be designed to offer coupling efficiencygreater than 70% between the light emitter and optical waveguide andsimultaneously greater than 50% between the waveguide and the opticaldetector.

Various exemplary embodiments can also provide a component that willfunction with single wavelength communication systems and withoutpreference to the polarization of the optical signals. The component canbe manufactured using high precision molding techniques. Precisionmolding techniques can create plastic or glass features defined toaccuracy of 5 microns or less. The component can contain elements toease alignment to optical waveguides, light emitters and/or lightdetectors. These elements can be molded into the component along withthe splitting surface and lenses associated with optical coupling. Asone example, injection molding of thermoplastics can be used as alow-cost method for producing the component, lenses, etc. within fiberoptic transmitters.

Various exemplary embodiments can provide a component that willwithstand temperature cycles of −55 C to 100 C. Also, some embodiment(s)can allow for the integration of OTDR within a fiber optic transmitterto provide built-in-test without sacrificing transmitter performancerequirements or physical size constraints. For example, this componentcan be implemented within a military grade fiber optic transmitter withan overall height constraint of 5 mm.

Also, a bi-directional coupling on each channel of a parallel (ormulti-channel) transmitter can be realized. A common format for aparallel transmitter is the use of multiple fiber optic waveguides on aspacing of 250 microns. Various exemplary embodiments disclosed hereoffer bi-directional coupling on each of the multiple waveguides withina parallel transmitter.

In one exemplary embodiment, the optical waveguide is a multimode fiber.The light source can be a vertical cavity surface emitting laser (VCSEL)and the light detector can be a PIN detector, which are mounted on atransparent substrate. Of course, other light sources and detector typesmay be utilized according to design preference. A surface that splitsthe light is molded in a formable material and is aligned to lenses forcoupling light to the multimode fiber and for coupling to the lightsource(s) and the detector devices(s). Nearly all of the light from thesource device strikes one or more surfaces oriented at an angle to thelight path. The light from these angled surfaces is reflected toward themultimode fiber due to the total internal reflection within the formablematerial. The light from the multimode fiber strikes the splittingsurface and passes through some regions within the light path. Theseregions are large enough to allow more than half of the light to passthrough and ultimately onto the detector. Also molded into thiscomponent can be an alignment guide pin for aligning the multimode fiberto a lens on the component and features to mount a reflector to directlight from the splitting surface into the detector. The light source anddetector devices are electronically connected to circuitry that performsthe OTDR function.

Bi-directional coupling efficiency is a concern for most electro-opticengineers. For example, let EW represents the fraction of optical energycoupled between the emitter (E) and waveguide (W), and WD represents thefraction of optical energy coupled between the waveguide (W) anddetector (D) in the reverse direction. U.S. Pat. No. 7,341,384, by Chanet al, discloses a method of bi-directionally coupling using an anglepolished fiber as the splitting surface. In this configuration, the bestpossible combination of coupling efficiencies, EW and WD, is unity(EW+WD=1). For example, if angle polish is 48 degrees, then 50% of thelight from the emitter will be directed to the fiber and 50% of thereturning light from the fiber will be directed to the detector. Thismethod relies on the time-invariance property of optics, meaning thesystem works the same way for light propagation in either direction.Another drawback of this approach is that the manufacturing method doesnot allow for the single step integration of coupling lenses. Lensdevices are needed in certain circumstances to aid in coupling. Forexample, when the fiber cannot be placed physically close to the lightemitter or light detector, a lens system forms a relay system betweenthe devices. The lenses would need to be manufactured separately andassembled as separate pieces within the transmitter package.

Conventional bi-directional coupling methods cannot achieve couplingwith EW+WD>1 for a single wavelength without control of thepolarization. A well known method of coupling light of achieving EW+WD>1with polarized light uses a polarizing beam splitter (PBS). A lightemitter with a known linear polarization can be oriented so that nearlyall of the light reflects at an angle of 90 degrees from the PBS. Ifthis light passes through a quarter wave plate (QWP), the light becomescircularly polarized. If this light were then directed back through thesame QWP and the PBS, the polarization would again be linearly polarizedin an orientation that nearly all the light would pass directly throughthe PBS without reflecting at 90 degrees and could be captured by adetector. However, the need to control polarization entails therequirement of devices such as QWPs, which add to the complexity andcost, as well as introduce optical loss.

As detailed herein, this disclosure describes exemplary embodiments withvery high combined efficiency of the coupling in both directions: 1)between the emitter and waveguide and 2) between the waveguide anddetector. Various exemplary embodiments allow bi-directional couplingwith EW+WD>1. This property can be achieved without regard to theoptical wavelength or polarization of the optical energy. Therefore, theexemplary embodiments can be utilized in products such as VCSEL-baseddata communication over multimode fibers, since a single wavelength iscommonly utilized and the polarization of the optical energy is notcontrolled.

Configuration

FIG. 1 is diagram of an exemplary system embodiment 1 for coupling lightbetween light emitter 3 and waveguide 2 using splitting surface 6 toturn light (shown lines 16) toward waveguide 2, and using this splittingsurface 6 to pass light from waveguide 2 to reflector 7. The reflector 7turns light toward detector 4. Structure 5 is disposed between the lightemitter 3 and waveguide 2 and contains lens 9 to couple light (shown byarrows 14) from light emitter 3 to splitting surface 6, lens 8 to couplelight between waveguide 2 and splitting surface 6, structure surface 12to mount reflector 7, lens 10 to couple light (shown by arrows 15)between splitting surface 6 and light detector 4, and stand-off 13 tocontrol the distance between lens elements 9 and 10 and light emitter 3and light detector 4, respectively. An optional transparent carrier 11can provide mechanical support for light emitter 3, light detector 4 andstructure 5.

FIG. 2 is a diagram of another exemplary system embodiment 68 forcoupling light (shown by arrows 15) between light emitter 3 andwaveguide 2 using reflector 7 to turn the light toward waveguide 2 anddirect the light through splitting surface 6 and into waveguide 2. Lightfrom waveguide 2 (shown by lines 16) is turned toward detector 4 bysplitting surface 6 and directed to light detector 4. Structure 5 isdisposed between the light emitter 3 and waveguide 2 and contains lens10 to couple light from light emitter 3 to splitting surface 6, lens 8to couple light between waveguide 2 and splitting surface 6, surface 12to mount reflector 7, lens 9 to couple light (shown by arrows 14)between splitting surface 6 and light detector 4, and stand-off 13 tocontrol the distance between lens elements 10 and 9 and light emitter 3and light detector 4, respectively. An optional transparent carrier 11can provide mechanical support for light emitter 3, light detector 4 andstructure 5.

FIG. 3 is a diagram of another system embodiment 72 for coupling lightbetween a light emitter 3 and waveguide 2 using splitting surface 6 toturn light toward waveguide 2, and using this splitting surface 6 topass light from waveguide 2 to light detector 4. Structure 5 is disposedbetween the light emitter 3 and waveguide 2 and contains lens 9 tocouple light (shown by arrows 14) from light emitter 3 to splittingsurface 6, lens 8 to couple light (shown by lines 16) between waveguide2 and splitting surface 6, surface 73 to mount light detector assembly76, lens 10 to couple light (shown by arrows 15) between splittingsurface 6 and light detector 4, and stand-off 13 to control the distancebetween lens element 9 and light emitter 3. An optional transparentcarrier 11 can provide mechanical support for light emitter 3 andstructure 5.

FIG. 4 is diagram of another exemplary system embodiment 84 that coupleslight from light emitter 3 through lens 9 onto splitting surface 6. Thelight from light emitter 3 passes through lens 9 and travels (shown byarrows 14) through splitting surface 6 to lens 8 via arrows 16 and iscoupled to waveguide 2. Light from waveguide 2 is coupled to splittingsurface 6 using lens 8. This light passes through splitting surface 6and is coupled (shown by arrows 15) into light detector 4 using lens 10.

FIG. 5 is a diagram of another exemplary system embodiment 88 thatcouples light from light emitter 3 via arrows 14 through lens 9 ontosplitting surface 6. The light reflects (shown by arrows 16) fromsplitting surface 6 and is coupled into waveguide 2 with the aid of lens8. Light from waveguide 2 is coupled to splitting surface 6 using lens8. This light reflects (shown by arrows 15) from splitting surface 6 andis coupled into light detector 4 using lens 10.

FIG. 6A is a diagram of an exemplary embodiment 92 using multi-stepstructural interfacial surface for splitting light. The light path 93contains sub-paths A, B and C that reflect from surface areas 96, 98 and100, respectively, and form a light beam containing sub-paths A′, B′,and C′, respectively, in the region of light path 95. Light path 95contains sub-paths V, W, X, Y, and Z that strike surface areas 96, 97,98, 99, and 100 respectively. Light sub-paths W and Y pass throughsurface areas 97 and 99, respectively, to form sub-paths W′ and Y′within light path 94. For light from light path 93, the light reflectsfrom the splitting surfaces 96, 98 and 100 in a 2-D pattern 102 withregions A′, B′ and C′. For light from light path 95, the light strikesthe splitting surfaces 96, 97, 98, 99 and 100 in a 2-D pattern 101 withregions W′, and Y′.

FIG. 6B is a diagram of another exemplary embodiment 106 using asingle-step structural interfacial surface for splitting light. Thelight path 110 contains sub-paths A and B that reflect from surfaceareas 122 and 124, respectively, and form a light beam path containingsub-paths A′ and B′, respectively, in the region of light path 118.Light path 118 contains sub-paths X, Y, and Z that strike surface areas122, 123, and 124, respectively. Light sub-path Y′ passes throughsurface area 123 to form sub-path Y′ within light path 114. Light fromlight path 110 reflects from the splitting surfaces 122 and 124 in a 2-Dpattern 132 with regions A′ and B′. Light from light path 118 strikesthe splitting surfaces 122, 123 and 124 in a 2-D pattern 128 with regionY′.

FIG. 6C is a diagram of another exemplary embodiment 136 using areflection mode structural interfacial surface for splitting light. Thelight path 140 contains sub-paths A and B that reflect from the surfaceareas 155 and 153, respectively, and form a light beam containingsub-paths A′ and B′, respectively, in the region of light path 148.Light path 148 contains sub-paths X, Y, and Z that strike surface areas153, 154, and 155, respectively. Light sub-path Y reflects from surfacearea 154 to form sub-paths Y′ within light path 144.

FIG. 6D is a diagram of an exemplary embodiment 160 using a transmissionmode structural interfacial surface for splitting light. The light path164 contains sub-paths A and B that pass through surface areas 176 and178, respectively, and form a light beam containing sub-paths A′ and B′,respectively, in the region of light path 172. Light path 172 containssub-paths X, Y, and Z that strike surface areas 176, 177, and 178respectively. Light sub-path Y passes through the surface area 177 toform sub-paths Y′ within light path 168.

FIG. 6E is a diagram of another exemplary embodiment 182 using anannular aperture splitting structural interfacial surface for splittinglight. The light path 186 contains sub-path A which reflects from thesurface areas 199 to form a light beam containing sub-path A′ in theregion of light path 194. Light path 194 contains sub-paths X, Y, and Zthat strike surface areas 198 and 199. Light sub-path X passes throughthe surface area 198 to form sub-paths X′ within light path 190. Ifviewed from the perspective of the light path 194, the light reflectsfrom splitting surface 199 in a 2-D pattern of region A′ and lightpasses through the splitting surface 198 in a 2-D pattern of region X′,as shown by the annular regions 204.

FIG. 6F is a diagram of another exemplary embodiment 208 using astructural interfacial surface for splitting light that is converging toa point. The light path 212 contains sub-path A which reflects fromsurface areas 224 to form a light beam containing sub-path A′ in theregion of light path 220. Light path 220 contains sub-path X that passesthrough surface areas 225 to form sub-path X′ within light path 216.

FIG. 6G is a diagram of an exemplary embodiment 230 using a structuralinterfacial surface for splitting light that uses a divisional lens. Thelight path 234 contains sub-paths A and B which are generated by a lens252 that creates a plurality of sub-paths. Sub-paths A and B reflectfrom surfaces 246 and 248, respectively and form light path 242 withsub-paths A′ and B′ resulting in the beam profile 254. The light path242 with sub-path X passes through surface area 247 to form sub-path X′within light path 238.

FIG. 6H is a diagram of an exemplary embodiment 260 using a structuralinterfacial surface for splitting light that uses a semi-reflectivesurface 276. The light path 264 contains sub-path A which partiallyreflects from surface 276 into sub-path A′ within light path 272. Lightpath 272 contains sub-path X which partially transmits through surface276 into X′ within light path 268. Semi-reflective surface 276 can be ahalf-silvered mirror, if so desired.

FIG. 6I is a diagram of an exemplary embodiment 280 using a structuralinterfacial surface for splitting light utilizing curved focusingsurfaces. The light path 284 containing sub-paths A and B is generatedfrom an optical source 3. Sub-paths A and B are reflected and focused bysurfaces 298 and 296, respectively to form sub-paths A′ and B′ withinlight path 292. Light path 292 contains sub-paths X, Y and Z generatedfrom a wave guide 2. Sub-path Y passes through surface area 297 to formsub-path Y′ within beam path 288 and couples to a light detector 4.

FIG. 7 is a diagram of an exemplary system embodiment 302 that coupleslight from a light emitting assembly 322 to a waveguide assembly 310using a light splitting assembly 330. This exemplary system also coupleslight from a waveguide assembly 310 to a detector assembly 326 usinglight splitting assembly 330. The light emitting assembly 322 contains alight emitting device 3 coupled to the light splitting assembly 330using a lens 314. The waveguide sub-assembly 310 contains an opticalwaveguide 2 coupled to the light splitting sub-assembly 330 using a lens306. The detector assembly 326 contains an optical detector 4 coupled tothe light splitting assembly 330 using a lens 318. The light splittingassembly 330 has an optical splitting surface 6 which reflects lightfrom the light emitting assembly 322 on light path 14 toward thewaveguide assembly 310 on light path 16. The splitting surface 6 alsodirects a portion of the light from the waveguide assembly 310 on lightpath 16 to a reflecting surface 7 which directs the light onto lightpath 15 toward the detector assembly 326. The light splitting assembly330 has features 12 that align the reflecting surface 7 to the splittingsurface 6.

FIG. 8 is a diagram of an exemplary system embodiment 334 that coupleslight from a light emitter 3 to optical waveguide 2 and from waveguide 2to light detector 4 using an optical waveguide coupling assembly 338 anda light emitter and detector coupling component 342. The opticalwaveguide coupling assembly 338 contains a lens 336 for coupling lightbetween the optical waveguide 2 and the splitting surface 6 on lightpath 16. The optical waveguide coupling assembly 338 contains features12 for aligning the reflecting surface 7 to the splitting surface 6. Theoptical waveguide coupling assembly 338 contains features 346 formechanical alignment to the light emitter and detector component 342.The light emitter and detector component 342 contains lenses 351 and 352for coupling to the splitting surface 6 and reflecting surface 7,respectively. The light emitter and detector component 342 containsstandoff features 350 to set the distance between the light emitter 3and the light detector 4 and the lenses 351 and 352. An optionaltransparent carrier 11 can provide mechanical support for the lightemitter 3, light detector 4 and the light emitter and detector couplingcomponent 342.

FIGS. 9A-B are diagrams showing a perspective view and plan view of anexemplary system embodiment 354 that couples light from an array of Nlight emitters 358, 359, . . . 358+(N−1) to an array of opticalwaveguides 362, 363, . . . 362+(N−1), and from an array of opticalwaveguides 362, 363, . . . 362+(N−1) to an array of detectors 368, 369,. . . 368+(N−1). This system contains an array of lenses 440, 441, . . .440+(N−1) that couples light from the optical waveguides 362, 363, . . .362+(N−1) to the beam splitting surface 410, which contains regions oflight splitting elements 414, 415, . . . 414+(N−1). The light splittingelements 414, 415, . . . 414+(N−1) direct light from the light emittercoupling lenses 390, 391, . . . 390+(N−1) toward the array of lenses440, 441, . . . 440+(N−1) and directs light from the array of lenses440, 441, . . . 440+(N−1) toward a reflecting surface 420. Thereflecting surface 420 directs light toward the array of detectorcoupling lenses 400, 401, . . . 400+(N−1). A bi-directional couplingassembly 380 is mounted on a transparent carrier 449. A single structure451 contains the array of lenses 440, 441, . . . 440+(N−1), splittingsurface 410, the light emitter coupling lenses 390, 391, . . . 390+(N−1)and the array of detector coupling lenses 400, 401, . . . 400+(N−1).

FIG. 10 is a diagram of an exemplary system embodiment 460 forperforming coupling between a bi-directional coupling assembly 464 and alight emitter 3 and light detector 4 which are electrically connectedvia electrical paths 472 and 476, respectively, to an integrated circuit468. The integrated circuit 468 is mounted on a “bottom-side” oftransparent carrier 480, which contains the electrical paths 472 and476. Additional circuitry 469 could be formed on the transparent carrier480.

FIG. 11 is a diagram of an exemplary system embodiment 560 forperforming coupling between a bi-directional coupling assembly 554 and alight emitter 3 and light detector 4 which are electrically connectedvia electrical paths 562 and 566, respectively, to an integrated circuit558. The circuitry is mounted on a “top-side” of carrier 570, whichcontains the electrical paths 562 and 566.

FIG. 12 is a diagram of an exemplary system embodiment 650 showingbi-directional coupling assembly 654 that contains features 658 that arein alignment with features 662 formed in a transparent carrier 666. Thetransparent carrier 666 contains a feature 686 that is in alignment tofeature 678 formed on the light emitter 3. The transparent carrier 666contains feature 690 that is in alignment to feature 682 on the lightdetector 4.

FIG. 13 is a diagram of an exemplary system embodiment 700 showing abi-directional coupling assembly 704 that is suitable for applicationsthat do not use an optical waveguide. The light emitter 3 is coupled tothe splitting surface 7 with a lens 9 in light path 14. The splittingsurface 6 reflects the light into light path 16 exiting the assembly704. Light entering the assembly 704 on light path 16 is partiallypassed through splitting surface 6 to reflecting surface 7. Light fromsurface 7 is coupled into the light detector 4 using lens 10.

FIG. 14A is an exemplary embodiment 710 of a communication linkimplementing OTDR. The transmitter 714 contains an OTDR function and issending information on an optical waveguide 716 to an optical receiver722. The optical waveguide 716 contains one or more opticaldiscontinuities 718. Using time-of-flight calculation, the transmitter714 can find the location of the discontinuity using OTDR methods.

FIG. 14B is an exemplary embodiment 726 of a bi-directionalcommunication link. The transceivers 730 are interconnected by a singleoptical waveguide 732. Information is optically transferred in bothdirections on this link

FIG. 14C is an exemplary embodiment 738 of a remote optical waveguidesensor system. The illuminator and sensor component 742 is linked withan optical waveguide 746 to an environment 750 under test. Theenvironment under test 750 varies the optical properties of the opticalwaveguide 746 which varies the optical reflectance of the waveguide 746.

FIG. 14D is an exemplary embodiment 754 of a free space opticalrangefinder. The illuminator and sensor component 758 transmits a lightpulse through free space on light path 762. The light is reflected froma remote object 766 and some of the light returns to the illuminator andsensor component 758 on light path 764. Using time-of-flightcalculation, the system 754 can determine the distance of the remoteobject 766 from the illuminator and sensor 758.

FIG. 15 is an exemplary embodiment 780 wherein the waveguide 2 and lens8 are in line with the splitting surface 6, lens 9 and light detector 4.In this embodiment, the reflector 7 may be integral to the structure 5,thus allowing light from the splitting surface 6 to be directed to lens10 and light emitter 3. Optionally shown is a transparent substrate 11disposed between structure 5 and the light detector 4/light emitter 3.

As is apparent from the various embodiments shown, multipleconfigurations and arrangements may be devised, once the generalprinciples having been explained herein are understood. Accordingly,many changes may be made to the embodiments described herein withoutdeparting from the spirit and scope of this disclosure.

Additionally, it should be understood that many additional changes inthe details, materials, steps and arrangement of parts, which have beenherein described and illustrated to explain the nature of the invention,may be made by those skilled in the art within the principle and scopeof the invention as expressed in the appended claims.

What is claimed is:
 1. A device for transmitting and reflecting lightbetween a plurality of lenses, comprising: a multi-sided transparentbody having a detector-emitter side, a waveguide side, a reflector side,and an indent with a light splitting surface formed as one piece withthe body at an interior end of the indent; a first lens formed as onepiece with the body at the detector-emitter side of the body; a secondlens formed as one piece with the body at the waveguide side of thebody; a third lens formed as one piece with the body at thedetector-emitter side of the body, wherein light from the second lens ispartially reflected by the light splitting surface to thedetector-emitter side of the body and partially passed by the lightsplitting surface; and upper and lower reflector-supporting angledsurfaces formed as one piece with the body located adjacent to and at anexterior end of the indent; and a reflector disposed onto the angledsurfaces, closing the indent, directing the partially passed light fromthe light splitting surface to the third lens and directing light fromthe third lens to the light splitting surface.
 2. The device of claim 1,further comprising: a standoff formed as one piece with the body to thedetector-emitter side of the body and providing a gap between at leastthe first and third lens from an end of the standoff.
 3. The device ofclaim 1, further comprising a transparent substrate having a lens sideand an opposite non-lens side, disposed exterior to the body, whereinthe lens side of the substrate is substantially adjacent to the firstand third lens.
 4. The device of claim 3, further comprising: a lightemitter disposed on the non-lens side of the substrate, and in alignmentwith at least one of the first and third lens; a light emitterelectrical contact disposed on the light emitter; a first contact pointdisposed on the non-lens side of the substrate, and aligned in contactwith the light emitter electrical contact; a light detector disposed onthe non-lens of the substrate, and in alignment with at least one of thefirst and third lens; a light detector electrical contact disposed onthe light detector; and a second contact point disposed on the non-lensside of the substrate, and aligned in contact with the light detectorelectrical contact.
 5. The device of claim 4, further comprising a firstlens electrical contact point on the lens side of the substrate and alight emitter/detector electrical contact point on the non-lens side ofthe substrate.
 6. A method for transmitting and reflecting light betweena plurality of integral lenses, comprising: forming a multi-sidedtransparent body with an indent therein, the body having adetector-emitter side, a waveguide side, and a reflector side; formingas one piece with the body a light splitting surface at an interior endof the indent, capable of passing and reflecting split light; forming asone piece with the body a first lens at the detector-emitter side of thebody; forming as one piece with the body a second lens at the waveguideside of the body, wherein the first lens and second lens are disposed ina reflected split light path of each other; forming as one piece withthe body a third lens to the detector-emitter side of the body, whereinlight from the second lens is partially reflected by the light splittingsurface to the detector-emitter side of the body and partially passed bythe light splitting surface; forming as one piece with the body aplurality of reflector supporting angled surfaces adjacent to and at anexterior end of the indent; attaching a reflector onto the angledsurfaces, closing the indent, the reflector reflecting light from thethird lens to the light splitting surface and reflecting light from thelight splitting surface to the third lens; positioning a light emitterin line with the first lens, positioning a light detector in line withthe third lens; positioning a waveguide in line with the second lens;positioning a reflector on the angled surface; emitting light from thelight emitter to be directed to the waveguide via the light splittingsurface; and receiving waveguide light passing through the lightsplitting surface and reflected from the reflector to the lightdetector.
 7. The method of claim 6, wherein time domain reflectometry isperformed by measuring a time delay between the emitted and the receivedlight.
 8. A method for transmitting and reflecting light between aplurality of lenses, comprising: forming a multi-sided transparent bodyhaving a first and second indent therein, the body having adetector-emitter side, a waveguide side, and a reflector side; formingas one piece with the body a light splitting surface at an interior endof the first indent, capable of passing and reflecting split light;forming as one piece with the body a first lens at the detector-emitterside of the body; forming as one piece with the body a second lens atthe waveguide side of the body, wherein the first lens and second lensare disposed in a reflected split light path of each other; forming asone piece with the body a third lens at the detector-emitter side of thebody, wherein light from the second lens is partially reflected by thelight splitting surface to the detector-emitter side of the body andpartially passed by the light splitting surface; forming as one piecewith the body a plurality of reflector supporting angled surfacesadjacent to and at an exterior end of the indent; attaching a reflectoronto the angled surfaces, closing the indent, the reflector reflectinglight from the third lens to the light splitting surface and reflectinglight from the light splitting surface to the third lens; positioning alight emitter within the second indent and in line with the first lens,positioning a light detector within the second indent and in line withthe third lens; positioning a waveguide in line with the second lens;positioning a reflector on the angled surface; emitting light from thelight emitter to be directed to the waveguide via the light splittingsurface; and receiving waveguide light passing through the lightsplitting surface and reflected from the reflector to the lightdetector.
 9. The method of claim 8, wherein time domain reflectometry isperformed by measuring a time delay between the emitted and the receivedlight.
 10. A device for transmitting and reflecting light between aplurality of lenses, comprising: means for light path manipulationhaving an indent, a detector-emitter side, a waveguide side, and areflector side; means for splitting light formed as one piece with themeans for light path manipulation disposed at an interior end of theindent; first means for focusing light formed as one piece with themeans for light path manipulation disposed at the detector-emitter sideof the means for light path manipulation; second means for focusinglight formed as one piece with the means for light path manipulationdisposed at the waveguide side of the means for light path manipulation;third means for focusing light formed as one piece with the means forlight path manipulation disposed at the detector-emitter side of themeans for light path manipulation, wherein light from the second meansfor focusing is partially reflected by the means for splitting light tothe detector-emitter side of the means for light path manipulation, andpartially passed by the means for light splitting; means for supportinga reflector disposed adjacent to and at an exterior end of the indent; areflector disposed onto the means for supporting, closing the indent,directing the partially passed light from the means for splitting lightto the third means for focusing light and directing light from the thirdmeans for focusing light to the means for splitting light.
 11. Thedevice of claim 10, further comprising: means for standing off formed asone piece with the body to the detector-emitter side of the means forlight path manipulation and for providing a gap between at least thefirst and third means for focusing light from an end of the means forstanding off.
 12. The device of claim 11, further comprising atransparent substrate disposed substantially approximate to the firstand third means for focusing light.
 13. A device for transmitting andreflecting light between a plurality of lenses, comprising: amulti-sided transparent body having a substrate side, a waveguide side,and light splitting surface side formed as one piece with the body; afirst indent disposed in the light splitting side of the body; a secondindent disposed in the substrate side of the body; a first and thirdlens formed as one piece with the body at an interior end of the secondindent; a second lens formed as one piece with the body at the waveguideside of the body; a light splitting surface formed as one piece with thebody at the light splitting surface side of the body, positioned toreflect a portion of light from the first lens to the second lens andpass a portion of light from the second lens to the third lens; upperand lower reflector-supporting angled surfaces formed as one piece withthe body, located adjacent to and at an exterior end of the indent; areflector disposed onto the angled surfaces, closing the indent,directing the passed portion of light from the second lens to the thirdlens; a light emitter disposed below the first lens and within thesecond indent; and a light detector disposed below the third lens andwithin the second indent.